The 5 Most Terrifying Side Effects of Exercise

#2. Swimming Can Kill You in Endless Creative Ways

We hinted earlier that if you're going to shit yourself while exercising, you might as well be in the water, where nobody would ever notice and the entire pool acts as your personal bidet. Plus, nothing bad ever happens to swimmers. Drowning? Surely a myth perpetrated by radical anti-transnatationists, right? No, swimming is perfect.

Now, this is not a problem for your local swimming pool. But what can beat the ocean -- or even a lake or pond -- for swimming? And once you advance to hard-core long-distance swimming like the swimming portion of a triathlon, you'll train in open water. Doing a mile in a 50-meter pool is repetitive and involves a lot of turning and stopping. Practicing out in a river or lake prepares you for the reality of not having a floor to stand on or an edge to grab and what to do when the inevitable tentacles wrap around your leg.

As long as it isn't too warm and the lake water too cold. There are nasties living in those depths, and not just alligator gars.

We speak of ancient horrors that have existed since before time, that lie dead and dreaming. And they'll infect and eat your brain. It's an amoeba called Naegleria fowleri, and it simply drifts into your nose and latches onto your olfactory nerve. Then onto your brain. It was thought to be exceptionally rare (with only a few hundred cases worldwide since it was discovered), and then all of a sudden in 2007, six people in the U.S. died from it. The amoeba needs warm water to live, and it's thought that its sudden growth is due to, you guessed it, global warming.

GettyWell, that good news almost makes up for the pandas dying out!

Not that warm water is great for swimming anyway, despite how awesome it feels. For instance, let's talk about sweat again. You sweat while you swim, just as with any other activity, but it does nothing. It's the evaporation of your sweat that cools you under normal circumstances. That doesn't happen while you're in water, but usually that's OK, because water is a giant radiator -- the heat of your body simply washes away. Unless the water is too warm.

In which case not only is your sweating ineffective, the water isn't cooling you. We're not talking hot-tub hot, just warm. In fact, any water above 80 degrees is probably too dangerous to exercise in.

Getty"I'm not moving from here on my doctor's advice."

#1. Your Junk Disappears

For you men out there, let's say you've decided to get even more manly by lifting heavy, manly objects and then placing them down again. Over and over, pumping those weights until your muscles fill with blood, your biceps swell, and you can see the visage of a young Schwarzenegger in your own face. After breaking a strong, manly sweat and staring at your sleek, chiseled form in the mirror, perhaps playing the tempo to the 1812 Overture with your pecs, you step into a manly shower to scrub the manly funk off your body. And it's in this shower that you discover you no longer have any balls. In fact, you've become a Ken doll.

Via Casey WestFun Fact: Stripping dolls and taking pictures of them makes you feel like a serial killer.

Whether you're a runner, a cyclist, a swimmer or some parkour jackass testing the patience of gravity, you'll soon discover that extended bouts of sustained physical effort cause your genitals to shrink. And by shrink, we mean literally tuck up into your body. Thankfully, one's genitals return to normal within an hour or so. Though it probably seems like longer.

Getty"I've just gone and bought throw pillows!"

As for the ladies, well, all you need to worry about is the female athlete triad, a condition that combines poor body image, eating disorders and menstrual irregularities. This particularly strikes women who engage in sports that reward lower-mass bodies -- like running, swimming and cycling, where less mass means less to move, which means greater performance.

The low body weight along with low caloric intake leads to brittle bones and amenorrhea, the loss of one's menstrual cycle for three or more months. Depending on the sport you participate in, you can expect a 3.6 percent to 66 percent chance of developing this, compared with the 2 percent to 5 percent chance experienced by the general public.

Though we suppose that being skinny, brittle and currently unable to become pregnant makes a woman the dream girl of the male douchebag. So you, uh, have that to look forward to.